This invention relates to a device for breaking up dirt and gravel within a culvert and the removal of the dirt from the culvert. Several types of culverts are used under roads where a stream or drainage ditch bridges the road. The culvert generally comprises either a concrete conduit buried under the road or a galvanized tin structure generally called a tinhorn which is buried under the road. After many rains, the dirt is washed from the open ditch into the culvert which fills up with dirt and gravel and other debris.
Heretofore, one of the methods used to clean the culvert out was to close the road and dig up the pavement. Gravel had to be removed and then the culvert was removed and cleaned by hand in a separate location. The culvert had to be replaced, the gravel placed around it, the road filled and pavement had to be replaced. This generally takes one to one and a half days depending upon the type of pavement used over the culvert.
Other methods used to clean out the culverts has generally included hydraulics wherein a long conduit having jets which point forward at the tip and several jets pointing backwards to pull the soil back along the hole. However, this requires considerable amount of time and water and creates a hugh mess. Further the hydraulic method only cleans a small hole so that the water can continue through and hopefully will wash out the balance of the dirt once a small hole has been formed therein.
Once the dirt has become compacted with gravel and other debris within the culvert it becomes very dense and hard to remove. Any attempt to remove all the dirt at one time is generally unsuccessul because the culvert will be pulled from the ground or the disc will be deformed or cable attached to the device will snap in half because of the forces developed by the huge amount of dirt and the resistance offered thereby.